Pulverizing-mill.



U. OROWELL.

PULVERIZING MILL.

APPLICATION FILED SEPT. 24, 1909.

1,091,042. Patented Mar. 24, 1914 I 3 SHEETS-SHEET 1.

G. GROWELL.

PULVERIZING MILL.

APPLICATION FILED SEPT. 24, 1909.

Patented Mar; 24, 1914L 3 SHEETS-SHEET 2.

G. GROWBLL.

PULVERIZING MILL.

APPLICATION IxLED SEPT. 24, 1909. 1 091 042, Patented Mar. 24, 19M

3 QHEETB-SHEET 3.

' COLUMBIA PLANOGRAPH co.,w/\smNo'r0N, D. c.

CLIFFORD CROWELL, OF MONTEREY, MEXICO.

IPULVERIZING-MILL.

Specification of Letters Patent.

Patented Mar. 24, 1914.

Application filed September 24,1909. Serial No. 519,416.

To all whom it may concern 5 Be it known that I, CLIFFORD CRownLL, a citizen of the United States, residing in Monterey, in the Province of Nuevo Leon, Mexico, have invented-certain new and useful Improvements in Pulverizing-Mills, of which the following is a full, clear, and eX- act specification.

The invention relates to mills for crushing or granulating, or pulverizing rock, quartz and various mineral ores and materials of a like nature.

The primary object of the invention is to provide an improved pulverizing mill of simplified construction, easily adjusted, and so constructed that all parts are of easy access for the purpose of making repairs.

- The invention relates more particularly to pulverizing mills in which a free ring is carried on supporting rolls to crush and pulverize the rock or other material by impact and a further object of the invention is to provide improved means for guiding the revolving ring to secure even wear on the ring and its supporting and operating rolls.

A further object of the invention is to provide an improved construction of the re volving ring in a mill of the class described, which will permit the ring to be worn until it becomes quite thin without danger of its becoming distorted, thus reducing the cost of repairs.

A further object of the invention is to provide an improved construction of revolv ing ring and cooperating rolls which will avoid sliding friction between the ring and stationary parts of the machine and insure a free running ring.

A further object of the invention is to provide improved means for excluding dust, which is generated in considerable quantities by the operation of the machine, from the bearings.

A. further object of the invention is to provide an improved construction in a machine of the class described in which the driving roll and the shaft supporting the same are rigidly supported for the purpose of securing even tension on the driving belt and making only one driving belt necessary.

A still further object is to provide an improved frame for supporting the crushing rolls and relieving the usual outer frame or housing from the strain of supporting the crushing rolls.

of structural steel construction.

character 13, be placed therebetween.

To the attainment of these ends and to the accomplishment of certain other new and useful objects, which will appear, the invention consists in the features of novelty hereinafter described, shown in the accompanying drawings and pointed out more specifically in the appended claims In the said drawings, Figure 1 is a side elevation partly in section of the improved pulverizing mill. Fig. 2 is a side elevation of the same, also partly in section, this view being at right angles to the View shown in Fig. 1. Fig. 3 is a detail partly in section of the yieldingly mounted ball and socket hearing for supporting the shafts of the lower crushing rolls. Fig. 4 is a side elevation of a modified construction of pedestal for supporting the operating parts, the same being Fig. 5 is a view similar to Fig. 4, but taken at right angles thereto and showing the driving pulley on the main driving shaft and the crushing rolls which do not appear .in Fig. 4. Fig. 6 is a detail sectional view showing a 'modified construction of the free ring.

Referring to the drawings and particularly to Figs. 1, 2 and 3, the free ring instead of being of the usual construction, which is that of an integral circular metallic member, is built up of two primary parts; first, an inner continuous ring of suitable =metal, as manganese steel, adapted to resist the wearing effect of the stone or other material to be crushed, this part being indicated by the reference character 10.

11 is an outer ring surrounding the ring 10 preferably composed of two segments, as illustrated in Figs. 1 and 2, and held around the inner ring Why a suitable number ofbolts as indicated at 12. In order to provide means for taking up any inequalities between the contacting surfaces of the circular members 10 and 11 and to provide resilient means between them, it is preferred that a circular strip of zinc or other suitable ductile material, as indicated by the referenfie T e free ring is primarily carried and rotated by the upper supporting roll which is secured to and rotates with the main driving shaft 14. This driving and supporting roll carried on the main driving shaft 14 is preferably composed of two parts, viz., an inner member 15 preferably tapered or in the form of a frustum of a cone and secured to rotate int With the main driving shaft 14: in any desired manner, being preferably shrunk thereon, as illustrated in the drawing, although it may be secured to the shaft 14 by a spline or other suitable means. Over the periphery of the inner member 15, which may be formed of cast metal and of relatively cheap construction, is an outer circular portion of suitable metal, as manganese steel, adapted to resist the wear of the crushing operation, the same being indicated by the reference character 16. This outer member 16 is preferably given a curved or oval peripheral surface corresponding with the slightly concave inner cooperating surface on the free ring. It is also provided with end flanges l6 which are adapted to retain the free ring in position on this roll. The peripheral portion 16 of the roll is preferably held in position on the inner member or core 15 of the roll by the use of one or more hook bolts 17 which have one end as indicated in Fig. 2, formed at an angle to lock the member 16 in position, the other end of the bolt passing through the opposite side of the member 15 and being threaded and provided with a threaded nut.

The main driving shaft 14 is journaled in suitable bearings 18, 19, supported on the main frame 20, and is provided at either or both ends with suitable driving pulleys as indicated at 21, which may be secured to this shaft in any desired manner, as by the splines or keys 22 inserted in cooperating grooves in the hubs of the wheels and the ends of the shaft in the usual manner. The journal bearings 18, 19, are preferably adjustably' supported on the top of the main frame 20 by means of the adjustable threaded bolts 23, provided with lock nuts 24:. For the purpose of providing a certain amount of resiliency between the bearings 18, 19 and the supporting frame, gaskets or strips of rubber, leather or other suitable material as indicated at 25 may be interposed between these hearings and their supporting portion on the main frame.

In machines of this character which are used for the purpose of grinding or pulverizing rock, quartz and other hard substances, it is very important that provision be made for excluding dust generated by the operation of the machine from the various bearings and moving parts. To this end the bearings 18, 19, are provided at each end with dust caps 26, provided With flanged portions entirely covering the ends of the bearings and held inposition on the shaft by means of suitable set screws 27 threaded into the dust caps 26 and impinging on the shaft 145. As a means of lubrication, the bearings 18, 19, are provided with suitable grease cups 28 which are provided with caps to exclude dust and which may be utilized to force lubricating material into the bearing by threading the caps thereon in the usual manner.

So far as I am aware in this class of machines it has heretofore been the common practice not only to mount the idle rolls within the free ring on movable bearings but the main driving shaft, or the shaft carrying the driving roll has also been mounted in movable bearings usually elastically controlled in relation to the main frame. Such construction has necessitated the placof driving pulleys on both ends of the main driving shaft and the use of double driving belts from the source of power, that is, a driving belt on each pulley of the main driving shaft in order to maintain the driving shaft and the driving roll carried thereby in proper relation to the free ring. Such construction has heretofore resulted in a main driving shaft and a driving roll of unstable character so that the variable movements of the driving roll have caused undue wear on the free ring and consequent loss of power. In the present invention these difliculties and objections heretofore found in this class of machines are obviated by mounting the driving roll and its supporting shaft in substantially fixed relation to the main frame as described. Within the free ring and below the driving roll other rolls are provided, preferably two in number as illustrated in the drawings, and are mounted to rotate with shafts which are journaled in bearings movable in relation to the main frame and to the upper driving roll. These lower rolls are preferably constructed just as the upper roll already described, being provided with inner cores 15 and an outer peripheral portion 30 which differs only from the peripheral portion 16 of the upper roll in that it preferably has no flanges, as it is found the flanges on the upper driving roll alone are sufficient to properly guide the free ring and as there lower rolls are movable and adjustably mounted in relation to the free ring and to the driving roll in order to prevent binding and consequent friction and wear, it is desirable that these flanges be dispensed with and the ring be left free to adjust itself to the surface of the idle rolls. The lower rolls, like the upper driving roll, are provided with the hook bolts 17 for retaining the peripheral portion in position on the inner cores. These lower idle rolls are secured to rotate with shafts 31 mounted at each end in movable bearings 32.

In Fig. 3 a detail of the bearings 32 is shown and from which it will be seen that the bearings 32 are provided with a central bulge or spherical portion as indicated at 33, the same being held within a corresponding bearing member 3 1 slidably mounted on member 35 which is adjustably secured to the main frame 20 by means of bolts 36. In order to secure the bearings32 in relation to the supporting members '34, straps 37 are provided and are secured at their extremities to the members-34 by suitable removable pins or bolts 38. This construction enables the bearings 32 to be readily removed for the purpose of replacing them, since to release them it is only neces sary to withdraw the pins or bolts 38 which secure the straps 37 in place. This construction is of great advantage and utility since it is frequently necessary to remove the lower idle rolls for the purpose of replacing the outer or peripheral portions which receive most of the wear. The bearing blocks 84 supporting the bearings 82 are not only slidably mounted in relation to the main frame as described but are elastically controlled by means of spring 40 contained within a suitable housing 20 on the main.

frame and having one end bearing against a fixed part on the main frame adjacent the bearings of the main driving shaft and reacting at the opposite end against a suitable block 41 movably mounted within the housing 20 and having threaded into it a suitable bolt 42 having a head provided with suitable means for turning the same to make adjustments and bearing against the slidable blocks 3a supporting the shafts carrying the idle rolls. In this manner the idle rolls are pressed downwardly along divergent lines radiating from the driving shaft and are held under elastic pressure against the inner peripheral wall of the free ring so that as the free ring is revolved by reason of its bein carried upon the upper driving roll and by reason of the downward pressure exerted on it by these elastically controlled free rolls, the material to be pulverized as it is discharged within the ring in the usual manner from one or both sides through the feed pipes 45 will be caught between the free ring and these rolls and crushed.

The free ring will be given sufficient speed, as in this class of machines, so that the material after passing between the free ring and the lower rolls will be carried upwardly by the centrifugal action due to the rotation of the ring, and will continue to be caught between the lower rolls of the ring and some of it between the ring and the upper driving roll until it shall be reduced to the required degree of fineness, when it will be allowed to escape from the machine by passing out of the machine at the discharge passage which begins at the lower side, as indicated most clearly in Fig. 2, between the inner wall of the main frame 20 and the side of the ring. The main frame 20 near the bottom of the ring in Fig. 2 is shown provided with a wearing plate 46, which is removable and may be replaced when wornand which may also be replaced by plates of varying thicknesses.

The two lower idle rolls, as stated, are not provided with flanges since they work on the coarser material near the bottom which would cause excessive wear by wedgingv between flanges, if they were present on these rolls, and the ring. The top or driving roll, which is provided with the side flanges, operates mostly on the fine material which is carried up by centrifugal force during the rotation of the ring and for this reason it is found that these flanges on this upper roll wear well and give satisfactory results. By means of the adjustment provided for the bearings of shafts 31 carrying the lower driving rolls, the ring may be made to travel in its proper relation to the rolls. Heretofore it has been the practice in pulverizing mills of this class to mount the bearings for each roll rigidly connected in relation to each other through a common frame which was acted upon by a single spring or other elastic means. In such constructions it has been found that a slight inequality of wear, due to uneven feed of the material to be crushed or other reasons, causes the ring to run out of proper relation to the rolls, resulting in grooving of the rolls, excessive wear, waste of power and reduced grinding effect. The only remedy in such cases and with such constructions is to replace the roll shells and rings with new ones, the old ones, when once so worn, being worthless. In the present invention, however, it is found that by making each bearing independently adjustable as described, the ring can be directed to its proper relation with respect to the rolls, thus avoiding the necessity of frequently removing and replacing them with new ones.

In the construction of this class of mills, in so far as I am aware, the free rings have heretofore been made of a single or integral piece of material or of a single thickness of materials bolted together and it has been found that when the ring becomes worn thin it is distorted by the pressure exerted upon it by the rolls and the material in the operation of the machine. Also, to resist wear it has been found that the ring and the rolls must be made of special metal at high cost. It is therefore desirable to wear these parts to the greatest extent possible. To accomplish this, particularly with the ring, which is the most expensive to construct of any of the single parts of a machine of this character, it is proposed, as described, to construct the inner portion 10 of a high-priced material capable of resisting the wear incident to its use while the outer portion 11 may be constructed of cheaper material but at the same time having the required strength. Heretofore when these rings have been constructed of high grade and high priced material throughout they have been found of sufficient strength in the beginning, but after being used and worn to a certain extent the rings lose their power to resist the crushing pressure and the entire ring must be replaced. In the present invention the outer ring of cheap and permanent material resists the strain and the inner portion of high grade and high priced material, after being worn until it can no longer be used, may be replaced without the necessity of supplying an entirely new ring, thus effecting a considerable saving in the cost of repairs and at the same time increasing the efficiency of the machine. The same is true of the rolls, the outer shells of which may readily be re moved and replaced with new parts without the necessity of renewing the entire roll.

To facilitate the removal of a worn roll shell or ring or other parts, the casing and main frame 20 may be conveniently formed, as shown in Figs. 1 and 2, with the upper portion made easily removable. The selfalining bearings 32 may be released by removing pins or bolts 38 from straps 37 or the entire bearing may be released from the main frame by withdrawing the securing bolts, indicated by the reference character 36, which hold the guide plates 35 in place. This leaves the roll and the shafts 31 free to be lifted out at either side.

It is in some cases desirable to make machines of this character of a construction such that no part will exceed a certain weight in order to facilitate ease with which the machine may be knocked-down for purposes of transportation. It is also sometimes desirable to construct these machines with a main frame of steel instead of east material, as illustrated in Figs. 1 to 3 inclusive, and to this end I show a modified form of the invention in Figs. 4 and 5, the main frame be ing of structural steel construction riveted or bolted together in sections so that the same may be easily taken apart, if desired, for transportation. In this modification of the main frame the bottom plate is indicated by the reference character 50 and to this is bolted a plurality of upright A-shaped pieces 51 to 56 inclusive. The main driving shaft 1 1 and its supporting bearings 18, 19, are the same as heretofore described and likewise the drivingv roll carried thereby. The free ring used with this modification of the invention is the same as heretofore shown and described and is omitted from these drawings. Likewise the construction of the free rolls is the same as heretofore shown and described but a modified form of supporting the bearings for the shafts carrying the free rolls is shown. These shafts are indicated by the reference character 55 and are provided at their extremities with closed end bearings 56, 57, preventing end thrust preferably provided with grease cups as indicated at 58.

The bearings 56, 57 are mounted in suitable bearing shells 59. These shells are provided with central portions adapted to receive end bearings 56, 57, and are provided with cylindrical ends some what extended mounted in guides secured to the main frame. This manner of mounting the bearings allows them to adjust themselves to perfect alinement with the shaft. The guides for supporting the members 59 are preferably formed with two segments bolted together, as indicated at 60, in order that one-half of these brackets may be readily removed which will release the members 59 carrying the bearings and allow the shafts and the rolls carried thereby to be readily removed. The fixed bearings 18, 19 are carried in suitable frames 62 bolted to the top of the main frame or pedestal and are provided with seats for the bearings which are adjustable in relation to the sup- )orting frame by means of set screws 63 As in the form of the invention already described in Figs. 1 and 2 the idle rolls on shafts 55 are downwardly pressed by suitable springs carried in the interior of their hollow upper cylindrical ends, these springs being indicated by the reference character 64 and having their lower ends impinged against a closed or contracted portion of this upper hollow cylindrical portion of members 59 while the upper ends of these sorings bear against suitable blocks 65 into which are threaded bolts 66 impinging at their upper extremities against the bracket or frame 62 which supports the upper fixed bearing. It is preferred that the upper extremities of these bolts be provided with capstan heads or other convenient means for taking a wrench or tool by which they may be adjusted. By this construction, as well as in the form shown in Figs. 1 to 8 inclusive, it will be seen that the idle rolls are spring pressed downwardly and outwardly from the fixed driving shaft as a center.

In Fig. 6 is shown a modified construction of the free ring. The inner continuous ring indicated by the reference character 10 is formed with its outer peripheral surface tapered from the middle toward each side and its outer supporting or surrounding portion is composed of two integral rings 11 and 11" having their inner peripheral surfaces formed at an angle to eoiiperate with the corresponding tapered surfaces on the inner ring. The parts 11 and 11 are shrunk or forced around the periphery of the inner ring 10 by reason of the tapered surfaces as securely as desired by means of a suitable number of bolts 12" passing through each and threaded and provided with threaded nuts. This integral construction of the outer supporting portions of the free ring possesses some advantages over the form previously shown and described in which the outer supporting portion is divided into segments, the chief advantage being a greater degree of strength with a given quantity of material.

In order that the invention might be fully understood, the details of the preferred embodiments thereof have been thus specifically described but it is not desired to be limited to the exact details of construction herein disclosed for it will be apparent that changes and modifications may be made by those skilled in the art without departing from the invention.

I claim 1. In a pulverizing mill, the combination with a main frame, of a flanged driving roll, a free ring carried on its interior by the flanged driving roll, and a plurality of flangeless crushing rolls held under elastic tension against the interior crushing surface of the free ring.

2. In a machine of the class described, in combination, a main frame, a driving shaft secured thereto and provided with a flanged driving roll, a flangeless single free ring carried by the driving roll, a crushing roll engaging the inner periphery of the free ring, a shaft on which the said crushing roll is mounted, a plurality of bearings for supporting the last said shaft in relation to the main frame, and independent elastic means interposed between each of said bearings and the main frame whereby the crushing roll is held under elastic pressure against the inner periphery of the free ring.

3. In a machine of the class described, in combination a main frame, a driving shaft mounted in bearings rigidly secured thereto and provided with a flanged driving roll, a single free ring carried by the driving roll, a flangeless crushing roll engaging the inner periphery of the free ring, a shaft on which the said crushing roll is mounted, a plurality of bearings for supporting the last said shaft in relation to the main frame, and independent elastic means interposed between each of the last said bearings and the main frame whereby the crushing roll is held under elastic pressure against the inner periphery of the free ring.

4:. In a machine of the class described, in combination, a main frame, a driving shaft mounted thereon and provided with a flanged driving roll, a single free ring supported on its interior by the flanged driving roll, a flangeless crushing roll engaging the inner periphery of the free ring below the driving roll, a shaft on which the said crushing roll is mounted, a plurality of bearings for supporting the last said shaft in relation to the main frame, and independent means for adjusting each of the bearings in relation to the main frame whereby the crushing roll may be brought into the desired relation with the free ring and the driving roll.

5. In a machine of the class described, in combination, a main frame, a driving shaft mounted thereon and provided with a flanged driving roll, a single free ring supported on its interior by the flanged driving roll, a plurality of flangeless crushing rolls engaging the inner periphery of the free ring below the driving roll, a plurality of bearings for supporting each of the crushing rolls onthe main frame, and independent means for adjusting each of said hearings in relation to the mainframe, whereby the crushing rolls may be brought into the desired relation with the free ring and the driving roll.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this ninth day of Sept, A. D. 1909.

CLIFFORD CROWELL.

Witnesses:

G. S. SAWYER, ARTHUR O. WHEATLEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Istelts, Washington, D. G. 

